Communications networks, such as next generation broadband networks, have become increasingly complex due to increased size, numerous intermixed technologies/protocols (e.g., ATM, Frame Relay, etc.), and the intermixing of equipment manufactured by numerous different vendors. As a result, network configuration management systems that can provision virtual trunks and circuits within these networks are becoming increasingly important. Such network configuration management systems function to determine the paths/routes between network equipment, herein referred to as network elements, and to communicate with those network elements to realize desired trunks or circuits that facilitate the transmission of traffic across the network.
In general, network configuration management systems have traditionally determined the paths available by modeling portions of network elements as nodes on a graph and the links/interconnections between these portions as links between the nodes. More particularly, prior systems typically modeled every port of every network element as a node on the graph and modeled every physical link that interconnected these ports to one another as links that interconnected the nodes of the graph. The network model was then used to provision virtual trunks, which formed paths between network elements in the network. Once these virtual trunks were provisioned, virtual circuits could then be established across these trunks to support traffic flow from one point to another in the network.
FIG. 1 shows an exemplary prior art network configuration management system 102 and a network 110 managed by system 102. The network configuration management system 102 functions to determine a preferred path between two points in a network (i.e., between two network elements) and for provisioning a communications connection across this path by communicating with the managed network 110. Managed network 110 consists primarily of broadband network 112 which, in turn, consists of a plurality of network elements 114-118 interconnected by physical links and virtual trunks and circuits represented in FIG. 1 by links 120-124. The network elements comprise varying technologies and protocols and may be manufactured by different vendors. Managed network 110 further comprises network management systems, such as network management system (NMS) 126, and element management systems, such as element management system (EMS) 128. These systems are typically provided by the network element manufacturers and typically function to perform the actual configuration and management of the individual network elements.
NMSs and EMSs may function to control both the network elements and the links between those elements. However some may not control the links between the elements and, instead, only manage the network elements themselves. For example, an NMS, such as NMS 126, may function to collectively manage a set of network elements 114 and the physical links 120 between them, thus forming a collectively managed sub-network having network elements 114. Accordingly, when network traffic arrives at an ingress port into one of the network elements 114, such as port 130, the NMS 126 determines a set of links and network element cross-connects to interconnect port 130 to an egress port, such as port 132. The NMS 126 then provisions the network elements to realize this interconnection. In another example, some management systems, such as EMS 128, may only manage one or more network elements 118, but not the links 124 between them. Here, a higher layer entity, such as the Network Configuration Management System 102, determines the links between network elements 118 required to create a path and then instructs the EMS to perform the necessary cross-connects within network elements 118 to realize the complete path.
FIG. 1 also shows how some network elements, such as network elements 116, are not managed by either an NMS or EMS. Specifically, a higher layer entity, once again such as Network Configuration Management System 102, directly communicates with these elements to perform network configuration functions. In this case, Network Configuration Management System 102 would configure any cross-connects within network elements 116 as well as any links between network elements. Thus, as shown in FIG. 1, to facilitate traffic flow across broadband network 112, for example from port 130 on network element 114 to network element 118, the combination of Network Configuration Management System 102, NMS 126 and EMS 128 will collectively determine an appropriate network path across and between network elements 114, 116 and then provision virtual trunks and circuits across network 112.
One difficulty with prior methods of using network configuration management systems, such as those described above, is that the modeling of the network elements, physical links, and virtual trunks and circuits results in very large, inefficient models that do not adapt well to diverse network elements and large networks. Specifically, such large models result in correspondingly large and complex network model graphs which, in turn, create performance and scalability issues due to the demanding processing requirements associated with such graphs. Therefore, in one prior attempt at solving this problem and to reduce the aforementioned disadvantages, a network model was created based on how the ingress and egress ports of each network element can be interconnected within themselves and to other network elements. Specifically, in this prior attempt, a simplified routing graph was created by the network configuration management system whereby, instead of modeling each port of a network element as a node on a routing graph, an entire network element itself could be represented as one or more routing nodes or, in some cases, multiple network elements could be represented as a single routing node. Referring to FIG. 2, for example, network elements 114 of FIG. 1 that are managed by NMS 126 are modeled as a single node 201. Additionally, network elements 118, which are managed by both EMS 128 and the Network Configuration Management System 102 are also modeled as a single routing node 204. Network elements 116 are each modeled as individual routing nodes, since the Network Configuration Management System 102 manages both the network element and the link between the elements. In such a model, therefore, the individual physical hardware links are not each modeled but, rather, one or more network elements are modeled as a single routing node based on how those network elements and the links between them are managed. Such an attempt is generally described in pending U.S. patent application Ser. No. 10/118,187, filed Apr. 8, 2002 and entitled “Determining and Provisioning Paths Within a Network of Communication Elements” (hereinafter referred to as the “'187 application”), which is hereby incorporated by reference herein in its entirety.